Switch to lithium battery on a Trial motorcycle.

I been planning on replacing the original batteries on the motorcycle with Lithium. The manufacturers of Lithium batteries promise a strong increase in riding time and significantly lesser weight.
But is that really the case?

Why Lithium batteries?

One of the biggest problems a electric motorcycle faces, is that you have to store the energy to the engine in batteries. The energy density is better (higher) in gasoline, and therefore combustion engine motorcycles can be made lighter than their electricity counterpart.
Therefore, one of the major challenges on an electric motorcycle is to ensure as efficient storage of the energy as possible – in this case having as much power available, with as low weight as possible.

There are different technologies at the market that addresses this issue. We chose to focus on Lithium ion battery technology, as it is possible to buy a ready-made “plug and play” packages for the motorcycle. Alternative technologies – for example, Lithium polymer – require you to start manufacturing a battery yourself and require major insight into the technology and a larger rebuild of the machine.

What’s the benefit?

The lithium-ion batteries have some advantages over the original lead batteries.

• Weight.
  Lead batteries are quite heavy. This results in lead batteries being more than 3 times heavier than their Lithium counterpart.
• Discharge
  A lead battery cannot discharge more than 80% and often a normal discharge will be about 50% (the latter is recommended by most manufacturers). A lithium-ion battery can be discharged close to 100%, resulting in more energy being available.
• Efficiency
  Lithium-ion batteries are more efficient when comparing to lead batteries – both in terms of charge and discharge. The lithium battery can hold the capacity for longer, and the Rider should not feel the large drop-off in effects, which is usually known when using lead battery.
  For example a motorcycle using lead battery technology will provide less and less power during a training, while the lithium counterpart will have more or less the same efficiency until the battery has completely discharged.
  
• Replacement
  The batteries have a longer lifespan, and can usually last for about 3 times as many discharges as a lead battery.
  
• Higher energy density.
  This results in the battery containing significantly more energy compared to weight.
  Normally, a Lithium battery can contain more than 3 times the lead battery capacity (by weight).

Naturally there are also disadvantages with lithium-ion batteries.
The primary is that they are more expensive to produce than a lead battery and require a special charger.
The batteries must be specially manufactured with a system that ensures that they are not fully discharged, over charged, must secure against short circuit and against overheating.

Purchase of Lithium Ion.

We quickly agreed that we would not try to produce a Lithium battery ourselves, even though there are many well-intentioned guides to this on the web. If you do not know exactly what you are working with, it can be a dangerous cocktail.

Boost-Bikes is one of the companies that specializes in producing these special Lithium batteries. It is a small company located in Ireland. If you have the OSET, batteries can be purchased directly via their website https://www.boost-bikes.co.uk/, in our case where it was a KUBERG bike, it required a phone call to specify the battery size and capacity (Boost-Bikes have delivered to KUBERG Hero before).

---

related articles on juniormoto.com

---

Installing the battery.

The installation of the battery is incredibly easy. Rear shield and sides are removed from the machine. Remove the original lead batteries. Clean the machine and install the new battery – it’s a snug fit.
New connectors are included, which fit directly into the original connectors. In total, the mounting takes about approx. 30 minutes. It is important that you ensure that nothing can “gnaw” the battery. You can do this by inserting a little shock absorbing material – we used a piece from a foam pad from a sleeping mat.

Remember to use a special charger for Lithium battery. In our case, this was included in the package from Boost-Bikes.

Is it worth the cost?

The short answer is yes.

Changing from lead to lithium battery gives an incredible effect.
On the KUBERG Hero we tested the lithium Battery pack on, the following applies.

Effective training time.
The effective training time has more than doubled.
Before the battery change, the maximum training time was approx. 2 hours.
We saw a significant drop-off in efficiency after 1 hour to 1.25 hours, resulting in the last hour of training not to be so effective. After switching to the new battery (a 15amp unit), the new training time is approx. 4 hours. There is virtually no drop-off in efficiency within this time.
The training was done with 50% max speed, and torque level 1 (lowest out of 3), and for approx. 15-degree Celsius (59 degrees Fahrenheit). This was the case for both training sessions, with lead battery and with lithium.

Maximum speed
Max speed was increased by 12%, measured via the Kuberg Volt application. Max speed was measured target without load.

Weight.
When converting from lead batteries to the new Lithium battery, a total of 8kg was removed from the motorcycle. This gives a weight reduction of as much as 25% in total weight on the motorcycle.
It should be noted that the weight reduction is taken from the top of the motorcycle (due to the location of the batteries on KUBERG Hero), which provides an additional advantage.

These improvements make an otherwise great motorcycle something really special.
It has become significantly easier for the rider to maneuver the motorcycle, and the weight reduction means that the machine can climb steeper hills than before. The ride time is also much longer, and with virtually no drop-off.
A little extra detail is that the motorcycle has now become easier for the Rider to pick up after a crash, due to the lower weight. In addition, the included powerful charger, allowed the charge time to be markedly shortened.

Overall, it is only advisable to change the battery to Lithium if you have the funds available. It is one of the best upgrade you can do!